


Keeping Warm

by Susanooh



Category: Fire Emblem Heroes, Fire Emblem Series
Genre: Age Difference, Breast Fucking, Cum Inflation, F/F, Futa Loli, Futanari, Huge Dick, Paizuri, Pedophilia, Sister/Sister Incest, Yuri, excessive cum, womb penetration
Language: English
Status: Completed
Published: 2018-07-26
Updated: 2018-07-26
Packaged: 2019-06-16 20:03:13
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,496
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15444777
Author URL: https://archiveofourown.org/users/Susanooh/pseuds/Susanooh
Summary: Ylgr is awoken on a cold night by her body's needs. Unable to ignore them any further, she goes to her big sister for help.





	Keeping Warm

The frozen, icy kingdom of Nifl, caked within a snowy expanse that held no respite for those not born native to its lands. The kingdom was subject to the brutal cold, especially during the winter months, sometimes to the point where even the people of Nifl itself were unable to bear the environment.

The kingdom was currently facing its worst winter blizzard yet. Nobody knew how long it was to go on for, and none left their homes for fear of being trapped in the growing snow. The cold was so severe that the common folk had begun to actually require the use of fire to keep themselves from the growing discomfort of the harsh cold. Despite the harsh conditions, it was actually a benefit to be born in Nifl at times like this, as any outsider bar the residents of the rival kingdom of Muspell would surely perish in the cold if they were not aware of the conditions beforehand.

The royal family of Nifl, too, were affected by the cold. Their lofty castle was positively covered in snow that reached high enough to block the front entrance. The family and their many workers were just as trapped in the castle as the commoners were, and as the four children did what they could to either help around or sate their boredom, the two ruling monarchs tried to figure out how to keep control of their kingdom during the disastrous blizzard.

However, it was the middle of the night, about 1 AM, and so the castle held a peaceful silence, save for the howling winds from outside.

The royal family's youngest child, Ylgr, was fast asleep in a bed that was much too large for the tiny girl. Being only seven (Though she was quite well-learned for her age) meant she had a lot of growing to do before this bed would be appropriately sized. Her chest rose and fell slowly with each of her unconscious breaths. Though, unfortunately for her, the small blanket that she had curled up underneath was now barely covering any part of her body save for her torso, thanks to a certain unwieldy part of her body that had pushed it off of her legs.

Ylgr was certainly unordinary, as from the girl’s crotch, pulsing and throbbing, was a massive, unreal monster of a dick. It was one that far surpassed putting adult men to shame and went into the territory of making horses blush. The leviathan had been with Ylgr since her birth, but it didn’t make itself known until very recently, when its growth suddenly skyrocketed, causing her to grow from a normal size for a child to… this in a matter of weeks, as well as developing a pair of testicles that matched in size. She knew that this was supposed to be a boy’s thing, and so inquired her older brother Hríd about it. The trembling, panting girl was promptly pushed out of his study, his awkwardness overtaking him when he attempted to find out how to explain the situation to her, or even to himself, really. He had urged her to try and hide the thing and make her way to her eldest sister, Gunnthrá, for help.

Gunnthrá was about as shocked as her brother was, yet she mostly kept her calm, as she always did, and after a bit of tripping over her own words in surprise, got Ylgr to play a ‘game’ with her. The game had Gunnthrá do strange stuff with Ylgr’s thing, rubbing her hands all over it, sticking out her tongue and swirling it around the bright red tip, and even pushing it into her massive breasts. This was a very unusual game, to say the least, but it helped relieve Ylgr of the swollen monstrosity. The game made Ylgr tremble in delight with foreign pleasures. However, Gunnthrá had abruptly cut the game short and made Ylgr go back to her room, telling her to just let it calm down on its own, as well as ordering her to never mention the game to anybody else. The big sister avoided Ylgr’s gaze for days afterwards, and it seemed like a slow process only for her to suddenly bounce back and act like the game had never happened, asking Ylgr what she was talking about if the girl brought it up again.

Ylgr shivered at the cold air that breezed through the room, twirling its way to her exposed legs and chilling the girl to her core. In response to the sudden, involuntary tremor, Ylgr’s dick spurted out a thick glob of the girl’s transluscent pre-cum. It flew through the air for an instant before impacting Ylgr straight on the chest, splashing droplets up onto her face. The girl stirred from her sleep in a start, sitting straight up in her bed. She gripped the shirt of her sleeping clothes between her index and thumb, immediately noticing the massive stain left behind, and then looked ahead to see her dick standing upwards. The girl huffed with her cheeks slightly puffed out, frustrated. She wasn’t a fan of all the problems this boy’s thing was causing for her. She couldn’t even go to her siblings for help, like she usually did for any problem. Her big bro refused to mention it, Gunnthrá acted like it didn’t exist, and Fjorm had no knowledge of it.

As little kids do for things that cause them the slightest inconvenience, she told herself that she hated it. She hated that weird spit-like liquid it dripped out, too. It wasn’t even tasty! The only good thing she had experienced from it was the game that her big sis played with her, but even then it was apparently a bad game, as Gunnthrá never wanted to mention it again.

Ylgr hunched over with her arms crossed, trying to look as irritated as possible while giving a child’s best death stare to her own cock, one that obviously went unresponded to, the monster still standing proudly against the cold air, engorged and awaiting the chance to breed with a suitable woman. The girl sighed exaggeratedly, lowering her arms to rest on the bed. She thought for a while, and then decided to go try asking Gunnthrá for help again. Her big sis wasn’t going to get mad at her, right? Plus, that game felt really good, and she wanted to play it again! And so, Ylgr, dragging a pillow into her arms and holding it close to her chest, sandwiching her dick between it and her own body, she hopped on over to her door and out into the darkly lit, white-blue-colored hallway of the castle.

Ylgr never liked the castle this late at night. She couldn’t see very well save for the occasional large windows that let moonlight shine through, illuminating her path just a little bit, and this night was particularly bad with the brutal, howling winds that could be heard all around the outside of the castle. Ylgr almost withdrew into herself from fright, hugging the pillow even tighter for comfort. The girl nearly died from shock when a window she had passed began to rattle as the wind beat against it, frozen from fear for a good minute after the shaking had stopped before she moved on.

Eventually, she reached the large door that lead to her big sister’s room. She reached out with a small fist and lightly knocked on the door.

“Big siiiiss… big siiiiiiisss.” She repeated the process of this knocking and whispering into the door’s frame. After looking around to make sure she was safe, she knocked a little harder and raised her voice just a bit.

Much to Ylgr’s surprise, as she tried knocking another time, the door flew open into the room. Her big sister, Gunnthrá, was standing there, the young woman’s mature, voluptuous body covered by her nightgown that was barely long enough to conceal her milky thighs. Her hair was fairly untidy, but still fell from her head in a pink waterfall, tipped off with yellow at the ends. The shoulder straps on her gown stopped just above the nipples of her gigantic breasts, hiding their entirety from the eyes of her sister, though they still slightly poked out, the shape of her areolas visible through the soft, velvety cloth. Even though her eyes were drowsy and half-opened they still held Gunnthrá’s signature sweet, caring gaze that could make a wyvern melt.

“Ylgr?” Her voice. Her heavenly voice that exuded her maternal and loving personality was able to fill Ylgr with a sort of fuzzy warmth that made her feel happy inside, even while standing in the cold halls of the castle. “What are you doing up so late?”

“I-I can’t sleep. The wind is too loud and it’s… scaring me.” Ylgr was a bit embarrassed to be admitting her fear of the wind, of all things. “Can I come in your room for the night? Please?” Ylgr gave a pleading look upwards to the woman who met her eyes, and was faced with her big sister’s smile, simultaneously warm and provocative in a way that Ylgr had yet to fully grasp.

“Of course.” With that, Gunnthrá stepped aside, allowing Ylgr full passage into her room. It was about as darkly lit as the rest of the castle, yet Ylgr felt a lot safer here than anywhere else save for her own room. The girl held a certain nostalgia for the room. Gunnthrá had become the de-facto storyteller to her younger sister over the years, the girl’s head resting on her soft lap until she drifted off to sleep, with her sister’s soft hands brushing through her hair and sitting for hours on end, content to just let the child sleep so close to her.

Ylgr turned around to face Gunnthrá, lowering the pillow from herself and letting her giant cock hang free as she watched her older sister close the door and turn around back to her, only for the young woman to nearly jump and sharply breathe through her teeth at the sight of the monster that hanged from the girl. The first thought, after the blank of her mind had cleared, was simple astonishment.

‘Gods, it looks even bigger than last time. And her balls are so huge.’ For a split second, thoughts such as this echoed in her mind, before she snapped herself back into reality. This was her sister, her seven-year old sister. Gunnthrá was certainly interested in exploring her sexuality, something she had no real opportunity to do, but incest, and especially incest with someone this young was out of the question for her, no matter how big their cock was, how meaty, throbby, veiny, swollen, delicious or-- or…  
Gods, this was going to be a long night.

“Big sis, can we, um… play that game again?”

“Ylgr, what did I tell you?” Gunnthrá said, putting on a stern tone, though it wavered a bit when her eyes locked onto the girl’s dick as it dribbled pre-cum onto the floor.

“Please, big sis? It felt really really good, and my thing is hurting really bad and it won’t go down. A-And the balls are really heavy and it’s hard to walk...” Gunnthrá took a good look at her sister’s genitals. She had a point, to be fair, her cock was engorged and swollen beyond reason, and her veiny balls hung from Ylgr’s crotch, looking like a pair of basketballs attached to a girl who could barely hold one in her hands. It wasn’t hard to believe that Ylgr had trouble walking with that… thing. It looked unwieldy, and wholly inappropriate on such a tiny girl.

Gunnthrá’s mind wracked itself as she reflexively put her hand to her chin as she began to think. If she were to play the ‘game’ with Ylgr, she’d pretty much only be helping her little sister, right? Calming down the girl’s dick was pretty important, and she considered the idea of Ylgr getting too backed up. She didn’t know how to masturbate, and if she didn’t cum soon it would eventually become a problem. It’d end up being a bigger problem than Gunnthrá just jerking off her sister to relieve her, right? So this was the right choice, correct? She was only helping the both of them and saving the rest of her family any future trouble, this was a good choice!

Or, maybe, that’s just her excuse.

Either way, Gunnthrá looked Ylgr in the eyes and gave another warm smile.

“Alright, alright. I’ll play the game with you.” Ylgr gained a huge smile across her face with a little gasp of excitement. “But, remember that you can’t tell anybody else, this is a secret between just us two, okay?”

“Mmhm! Secret! I promise!”

“Good.” Gunnthrá approached Ylgr, now with a bit of a seductive sway to her hips. As she reached the girl, she squatted down, lowering her head to just above the base of the girl’s cock. Reaching out, she gripped its length, making her sister give a short moan as Gunnthrá lowered its large, red tip down to her large lips. One hand was slowly stroking across the beginning portion of the beast, while the other held it up in its palm. Gunnthrá gave the crown slow, soft, loving kisses across its top side, causing the entire cock to spasm and spurt out pre-cum against Gunnthrá’s neck, splattering down onto her large chest. Ylgr’s trembling hands gripped onto the hem of her shirt as Gunnthrá began to flick her tongue across her tip before opening her mouth fully and devouring a full six inches in one go. Ylgr almost fell forwards, wrapping her arms around Gunnthrá’s head for support as her legs quivered. The girl’s position suddenly forced a large chunk of herself forwards, invading Gunnthrá’s mouth and throat, stretching out her jaw to accommodate its width. It took all of the effort the young woman could manage to hold back her gag reflex, having to stop and try to focus before resuming. She slowly began to bob her head back and forth, feeling the rock-hard appendage snake its way through her esophagus, every definition of its veins and especially its tip making itself very familiar with the inner workings of Gunnthrá’s throat.

“Big siiiisss! Big siiiiiiiiiissss!” Ylgr, meanwhile, was having the time of her life as she felt her big sister’s throat stretch against her. The girl felt a strange feeling well up within her crotch and the entirety of her cock, one that made her pant like a dog in heat. Her body urged her into shoving her hips forward even more, violating her sister’s body further. In only a matter of a few seconds, Ylgr had hilted her entire cock within Gunnthrá’s mouth. The big sister’s eyes rolled back as she was harshly facefucked, holding onto her sister’s hips as the girl slammed into her mouth over and over again, her massive balls, engorged to bursting with gallons of virile semen, slapping against the young woman’s chin with every thrust.

Gunnthrá didn’t want to stomach the undoubtedly gigantic orgasm that Ylgr had in store for her, and through her trance she gripped onto Ylgr’s hips and pulled the girl out of her mouth, forcing herself to feel as the entirety of Ylgr’s cock was pulled out of her body in one quick motion. Ylgr tried in vain to thrust her dick into Gunnthrá’s mouth once more, but her big sister held the child at bay as she coughed harshly to the side and groaned while regaining her footing. Standing up, Gunnthrá carried a now-confused Ylgr in one arm as she slipped off her nightgown with the other.

Placing the child on the bed, Gunnthrá gripped the base of her cock as she slipped her nightgown down, unveiling her massive breasts. Ylgr watched in amazement, and then ecstasy as her big sister took the underside of her breasts into her hands, parting them together while lowering her chest to the girl’s crotch, and then slamming them together, sandwiching and enveloping the gigantic cock in-between them.

“Mmh!” Ylgr kicked her legs and squeaked out tiny, adorable noises as she was overwhelmed with Gunnthrá’s soft, heavenly titfuck. On Gunnthrá’s part, she too moaned as her tits were slicked over by the child’s pre-cum. Her breasts were always fairly sensitive to touch, and feeling her sister’s powerful, warm cock throb against them was good, really good. By the gods, if she was given the choice right now, she would be content just titfucking her sister for life, feeling this monster between her breasts 24/7.

Gunnthrá cooed as Ylgr grabbed onto her big sister’s shoulders for leverage and began to thrust upwards into the woman’s tits. Her mouth was about to limply hang open, only for Gunnthrá to lean forwards, pressuring her mammaries down against Ylgr’s cock to give the child a deep, sloppy kiss. Both of them moaned into each other’s mouths as Gunnthrá continued to pump her tits up and down the completely covered dick. Gunnthrá’s closeness prompted Ylgr to move her arms and wrap her big sister into loving embrace as their kiss and foreplay continued. Briefly, Gunnthrá broke off the kiss, staring down at the little girl whose mind and body was being assaulted by bliss.

“You’re so cute when you fuck my tits so hard. You wanna cum, don’t you? Give it all to me, lil sis, give your big sister all of your hot, sticky cum, shoot it all over me!” Gunnthrá’s sudden dirty talk and cursing surprised Ylgr, this wasn’t how her big sister normally behaved, but she really wasn’t one to complain about it with how good everything felt right now. “You can do it, Ylgr. Don’t you want to cover your big sis in your cum? Don’t you want to mark me as yours? Come on, come oonnnn~!”

“B-Big sis!” Ylgr shouted as she thrust upwards into Gunnthrá’s cleavage, locking herself in that position with her tip still sandwiched between the massive breasts as her balls tensed and their tension was relieved all over Gunnthrá’s chest. Cum splattered against the inner crevice of the woman’s chest, almost totally coating her cleavage before it began to well up from the fleshy canyon and drip down in large globs from the underside.

“Mmh~! That’s what I- Oh!” Gunnthrá was cut short as a massive glob of the child’s cum erupted from her breasts’ crevice, launching high into the air before flying back down and splattering all across Gunnthrá’s chest, some of it even splashing up onto her face. “Goodness, that one was really forceful!”

“Mmmgh… Haaaaahh… Big siiiss.” Ylgr moaned out as her orgasm finally subsided. She was left dazed and feeling as though she had been spun around too fast to handle, her young mind barely able to still comprehend what she had just gone through. She involuntarily arched her back as Gunnthrá slowly pulled her tits off of the girls cock, letting the pole go from its pillowy prison. Small droplets of girlcum flew out and fell onto Ylgr’s own body.

Gunnthrá began to run her hand across her chest, as it was now absolutely soaked in cum, and began to needily slurp up whatever her hand could pick up, moaning as she let her little sister’s fluids fill up her stomach.

Through her lusty daze, Ylgr watched Gunnthrá as she cleansed herself of the girl’s sticky goo. Even after her attempted cleanup, her chest was still peppered with splotches and droplets of cum. Gunnthrá let the last clump settle in her mouth, almost chewing on it and rolling it around in her mouth to let her tongue become acquainted with her little sister’s flavor.

With an almost audible swallow, Gunnthrá consumed the last large glob of semen she could handle, moaning a “Mmmmh~” all the while. She let an especially warm breath out as she absentmindedly rubbed a hand against her full stomach. Originally, she had planned to just get Ylgr to cum once and then get her to sleep again, but her gushing pussy decided otherwise, and was even more deadset in the opposite as she noticed that Ylgr’s cock had failed to falter and soften, even after cumming what had to be more than a gallon.

By now, Ylgr seemed to have been able to get control of herself again, and she sat up on the edge of Gunnthrá’s bed, watching as her big sister finally fully removed her nightgown from her torso, letting it fall to the ground fully. The young woman slept in her underwear, and so her soaked panties were entirely visible now. Trails of her feminine juices flowed from the edge of her panties and down her thighs. She bit her lip as her thumbs hooked on the straps of the garment and slid them off her legs.

Standing at the edge of the bed and turning around, displaying her large ass to her sister, Gunnthrá began to slightly lower herself, causing the Ylgr’s dick to poke and prod at her sizeable rump and crotch as she attempted to bring her vagina down onto the monster below her.

Eventually, she found the sweetspot, grinding her cunt against Ylgr’s tip for a moment before beginning the plunge, pushing back up against Ylgr to fill her insides up. Her mouth hung open as she let out a long, groany moan as she felt the beast spear itself inside her, twitching as she felt all of the girl’s veins rubbing, grinding against her vaginal walls. Gunnthrá struggled to fit the rest inside her, grunting as she tried to force all of it in.

“You’re-- Ah!- Bigger than you look, Ylgr!” Eventually, Gunnthrá’s body put up some resistance once the girl’s dick started to prod at the woman’s womb, her cunt stuffed full of child dick. “Mmf…” She goraned out as she began to gyrate her hips around. She intimately felt her sister’s tip poking the entrance to her womb. She was unsure about what’d happen if she pushed further, and decided to play it safe. After all, she was able to fit a good portion of her sister’s dick inside as it was ‘Alright Gunnthrá, just keep moving around…’

Both the woman and her little sister couldn’t contain their moans at all as Gunnthrá began to thrust her hips back and forth, picking up the pace tremendously from the insertion. When she’d go as far down as she could, Gunnthrá would circle her hips around for just a moment, getting an adorably pleasured groan of Ylgr every time.

“B-Big sis… I want… deeper…” Ylgr barely managed to whisper out.

“Hm?” Gunnthrá was a bit too busy with shoving Ylgr’s cock in and out to have caught what her sister was saying, but Ylgr made it known when she grabbed onto Gunnthrá’s hips and shoved her own forwards, forcing her dick to push down on her big sister’s womb.

“OoooOOOOHHHHH~?! Y-Ylgr, shtop-- Ahh!- Stop that!” She begged. A mix of bizarre pleasure and pain shot through the woman as Ylgr’s dick began to force its path open. The sudden sensation made Gunnthrá fall down to her knees, her ass pointed skywards, with Ylgr following suit. “Please, stop! You’re going too deee-HEEEEEEEEP!!” Gunnthrá screamed as she felt her sister’s tip begin to push through the barrier that was blocking it, opening up the tight hole.

Gunnthrá fought back the tears that had begun to form in her eyes. She had never had anything go this deep, not even her dildos. The immense pleasure she had been feeling now blended with a fear on if this would permanently damage her in any way. The pain certainly made it feel that way.

“Big sis it’s… so tight!” Ylgr yelled as she pushed another inch inwards. With the woman’s womb opened, Ylgr was able to slip in the rest of herself inside, finally going balls-deep on her big sister. Gunnthrá could feel the monster prodding around in her womb. Moving her head, she could see that it had produced a noticeable distention on her belly. The woman could barely respond to anything as Ylgr began thrusting in and out, pushing back into her womb every time.

Loud, wet slaps resounded through the bedroom as Ylgr began roughly fucking her sister, fast and hard. Both girls were unable to produce any noises aside from their moans and occasional screams of pleasure.

“B-Big sis… the thing from before is happening again…” Ylgr groaned out as she felt her balls tense up, cauldrons full of hot cum that was just waiting to erupt outwards.

This was it, Gunnthrá couldn’t fight back, she probably going to be impregnated by her seven-year-old sister. Surprisingly enough, she didn’t feel like fighting back. It felt as though the moral questionability of the situation completely vanished from her mind. Right now? All she wanted was to feel that hot, thick fluid flowing through her.

“C-Cum inside, Ylgr… Big sis will take it all…”

“Big sis-! Ugh!” Ylgr shouted for one last time as her nuts contracted. Erupting from her dick was a massive load of her hot cum, depositing itself directly inside Gunnthrá’s womb.

“Yes! F-Ffill me up, please!” Gunnthrá shouted as countless more waves of the fluid filled her. Load after load, Gunnthrá’s stomach began to grow, distended into a large, round shape as it contained her sister’s cum. After what had to be more than a gallon filled her, her body refused any more, and forcefully exited the excess cum out of her womb, flowing back through her vagina and spurting out, splashing up against Ylgr. Even so, Ylgr didn’t stop, and she kept forcing her unreal load into Gunnthrá. A puddle of cum flowed from them, growing further and further, turning massive and taking up a good portion of the previously clean floor.

After several minutes, Gunnthrá and Ylgr both felt the girl’s dick calm down, it’s stream of cum slowing down before halting completely.

Ylgr slowly pulled her dick out of her big sister, stumbling over and landing on her behind when she finally exited. Ylgr could barely keep herself sitting upright, and Gunnthrá was left lying down in the pool of girlcum that Ylgr had produced, both of them left drenched in the liquid. The young woman that had taken it all was left already looking like she was extremely pregnant.

The two panted and tried to catch their breath in the calm. But both were snapped out of their trance as they heard the door to the room open up.

“Gunnthrá! Can’t you be quiet- Oh.” Standing there was the middle sister of the royal family, Fjorm, in her own nightgown that hugged her body similarly to Gunnthrá’s. “I- Uh… Nevermind.” The girl quickly exited the room, closing the door behind her.

Gunnthrá let out an exasperated groan in annoyance. This was going to be hard to explain.


End file.
